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Recovery Catalog
How will you find out if your database is using recovery catalog or not?
ianilreddy
- Aug 7th, 2010
Using catalog database we can find if the database registered or not in recovery catalog database? SELECT * FROM rc_databaseWhere we can find all the registred databases;
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What is Dedicated Server and Shared Server?
ianilreddy
- Aug 7th, 2010
Dedeicated server: For one user one server processsesShared server: Where multiple user and one server process. In shared server whenever user request, server hands over the request to dispatcher and...
sharmme
- Feb 17th, 2010
In a Dedicated server mode, listener spawns a dedicated server process for each user process where as in shared server mode, listener assigns a dispatcher to each user process from the available ...
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What happens if i kill a mandatory background processes?
krish_makkena
- Aug 4th, 2010
If we kill the mandatory background processes the db should be shutdown i.e, instance is terminated.
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How to recover the DB if we lost controlfile and we are not having backup also and the database is down...?
shekar2130
- Jul 15th, 2010
If we are loosing control file then we will take backup of control file from alertlog file.
rharijan
- Sep 2nd, 2009
If controlfile is lost we can go to the trace file in udump and there after we can create control file by copying the datafile and redologfile and paste in user managed backup by giving old location to a new new location and then try to recover the old one giving the reuse option.
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Database Buffer Blocks
How many type of database buffer blocks are available? What are they?
shekar2130
- Jul 15th, 2010
There are 3 types of buffers present:1. Free buffer2. Pinned buffer,3. Dirty buffer
sharmme
- Feb 17th, 2010
Following are the types of Buffer blocks available.Pinned - Marked not to be released as per LRU algorithm. These are marked as required for further writes/changes/reads by transactions.Dirty - Change...
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How to grant complete database access to an user as read only...?
mangeshchede
- Mar 21st, 2010
By using following SQL Command you can grant read only privillege to your user on whole database.SQL > grant select any table to user_name;and dont grant any other privilege to that user.
rajendra_thanekar
- Apr 9th, 2008
Hi,You can put the entire database in read only mode.startup mountalter database open read only;
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Hard Disk Crash
What will happen in database if your like hard disk crashes & what will be your next step to recover that database?
mangeshchede
- Mar 21st, 2010
If your Harddisk gets crashed then If your Database is in Archive Log Mode, you should recover your database by applying all Archives or by restoring the latest backup.
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Database Status
How will you check the database status from os level in a unix env ?consider that some of the instances are in mount state; hence checking the pmon os process will be vain..? Need a unix os command to check if the databases are up and running
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NoArchiveLog Mode
A Database is running in NoArchiveLog mode then which type of backups you can take?
mangeshchede
- Mar 21st, 2010
If your Databse is in No Archivelog Mode then you must take a Cold backup of your Database.
naveen_rc
- Aug 4th, 2009
If your database is in NOARCHIVELOG mode, then the only type of backups that you should perform are closed, consistent (COLD BACKUP), whole database backups. The files in this type of backup are all consistent and do not need recovery, so the online logs are also not required.
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DBMS analysis and Requirements
Imagine that you joined a company as DBA and your first task is to create test and production database environments for application developers and users. How would you analyze requirements for a new DBMS? Write your answer according to the requirements of Oracle 9i or 10g Enterprise database system.
vdamodharan
- Jan 20th, 2010
That depends on what role you are playing in the DBA team. If you are a operation DBA, then all you need to know to create a database are: Initial sizing, redo, archive log size. The...
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Can RAC structures have different operating system nodes in cluster. e.g one node linux and other node is Windows. if not then why?
arulibra
- Jan 13th, 2010
No, you cant have different operating system in different nodes. All the nodes should be of same hardware, same OS, same version of cluster ware and RAC software. Even the oracle software and operatin...
parthokonar1
- Sep 26th, 2007
No it cannot be all the nodes have to be same os/platform. before oracle installation RAC software has to be installed. for load balancing etc
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Reading Oracle Control file content
Can we read Control file? If yes, then how?
lakshmi143.e
- Oct 14th, 2009
SQL> ALTER DATABASE BACKUP controlfile TO trace;
You can find the trace file which is backup of control file in udump directory.
narendra05
- Oct 2nd, 2009
Control file is the metadata of data and the information is stored in binary format. Some part of the control file can be seen by tracing it to trace (struncture of database can be seen by tracing th...
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If you 100 table spaces so how to find which table space is growing and which one is volatile?
narendra05
- Oct 2nd, 2009
In 10g the AWR repository keeps track of data for 60 days by default and can store the information of tablespace growth for this period.Alternativey you can set the threshold in entreprise manager for a tablespace to respective which can trigger email alert if configered.
hemant.agarwal03
- Mar 17th, 2008
Select sum(bytes),TABLESPACE_NAME from dba_segments group by TABLESPACE_NAMEorder by sum(bytes) desc/
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Why data reshuffling is required?
saurabh.nigam27
- Sep 16th, 2009
Due to DML commands, HWM will increase, which means for a query till the HWM all the blocks will be read whether blocks contain data or not (due to delete), because of this performance will go down.
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How can you find all the tables created by an user?
bapiora
- Jun 29th, 2009
As?a dba if you want such info. from your database side.You issue following command from server end.?? select owner,table_name,tablespace_name from dba_tables or if you need some specific user info. issue?? select owner, table_name ,tablespace_name from dba_tables where owner='< username>'
subha gunasekaran
- Jun 5th, 2008
select sum(bytes)/1024 from dba_segments where segment_name='TABLE_NAME' and owner=' 'As segment_name represents table_name,index_name..provide the table_name and index_name in the above query
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Target Database RMAN Backup
What are the steps required to enable the RMAN backup for a target database?
bapiora
- Jun 29th, 2009
Open a RMAN session and connect with target database, if you follow standalone command method just issue BACKUP DATABASE?command its allocates channel and do the backup, but if you follow batch comma...
anuradhad
- Feb 24th, 2009
Steps required for RMAN1)create a user to hold the recovery catalog2)Grant connect,resource,recovery_catalog_owner to the user3)Create recover catalog4)Register database.Each database to be backed up by RMAN must be registered
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Logical online backup
Can you take online backup of a Control file if yes, how? Explain about Logical Backup?
bapiora
- Jun 29th, 2009
During database online you perform logical online backup for control file. ALTER DATABASE CONTROLFILE TO TRACE Through this command you perform? control file trace backup which is logical.
impalor
- Dec 9th, 2008
You could use alter database backup controlfile for a binary copy of control file.
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Two Phase Locking Protocol
Explain the concept of two phase locking protocol with an example?
dhs01
- Apr 15th, 2009
Not sure of the particular terminology but 2 phase locking I believe would be similar to 2 phase commit where you must first make sure that everybody involved is ready, able, and willing (phase 1) then the next phase is when it actually happens (phase 2).
rpeters83
- Dec 9th, 2008
I'm no DB admin but I'll give it a shot. It's a protocol gauranteed to allow serialized actions on a database by having a locking phase and an unlocking phase. Meaning, during locking, no other transactions may be performed on the database until it is unlocked.
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High Water Mark
What is High Water Mark in Oracle?
DPsireesha
- Feb 24th, 2009
The High Watermark is the maximum fill-grade a table has ever reached. The blocks above high water mark are empty blocks.Initially when you create a table the high water mark is the first block. When ...
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What is BITMAP index and B-Tree Index in Oracle 10g
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raja_wipro
- Dec 2nd, 2008
In Oracle 10G we do not have Bitmap Index . Bitmap index is available only in Oracle9i Enterprise Edition
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